The White House on Tuesday did not ruled out the possibilities that a new U.S.-Russia nuclear arms control treaty could not be concluded before the Nuclear Security Summit in April, saying it would not rush the negotiations before the summit.

"They are working on the last few remaining issues to a new treaty and we are certainly hopeful that that can be done in short order," White House spokesman Robert Gibbs said, but adding "We're not looking to rush the negotiations in order to ... have a signing ceremony prior to that important meeting with countries throughout the world."

Negotiators from the two sides, now in Geneva, still have been trying to hammer out a new nuclear arm control treaty to replace the Strategic Arms Reduction Treaty (START), which expired on December 5, for some months. Russian President Dmitry Medvedev said last week that the two sides are "close to agreement."

Under the new and more ambitious initiative, backed by President Barack Obama and President Medvedev, the nuclear warheads each side holds are expected to be reduced to 1,500 to 1, 675, while the launchers to be limited to 500 to 1,000. Both Obama and Medvedev consider the arm control process as a vital step to boost mutual trust between the two countries.

The two leaders have vowed to work together in the spirit of the START treaty following its expiration, in order to ensure that a new treaty on strategic arms enter into force at the earliest possible date. Reports here said that the new treaty is expected to be signed at the Nuclear Security Summit, which will be held in April 12 to 13 in Washington.